Added read files + lookup

2026-06-19 21:37:32 +02:00
parent 50cb21b9e5
commit 872580602d
3 changed files with 170 additions and 22 deletions
@@ -106,6 +106,12 @@ dependencies = [
 "hashbrown",
 ]

+[[package]]
+name = "itoa"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
+
 [[package]]
 name = "libc"
 version = "0.2.186"
@@ -149,6 +155,7 @@ dependencies = [
 "ctrlc",
 "fuser",
 "libc",
+ "serde_json",
 "time",
 ]

@@ -333,6 +340,15 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"

+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+]
+
 [[package]]
 name = "serde_core"
 version = "1.0.228"
@@ -353,6 +369,19 @@ dependencies = [
 "syn",
 ]

+[[package]]
+name = "serde_json"
+version = "1.0.150"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8014e44b4736ed0538adeecded0fce2a272f22dc9578a7eb6b2d9993c74cfb9"
+dependencies = [
+ "itoa",
+ "memchr",
+ "serde",
+ "serde_core",
+ "zmij",
+]
+
 [[package]]
 name = "smallvec"
 version = "1.15.2"
@@ -490,3 +519,9 @@ dependencies = [
 "quote",
 "syn",
 ]
+
+[[package]]
+name = "zmij"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
@@ -7,4 +7,5 @@ edition = "2024"
 ctrlc = "3.5.2"
 fuser = "0.17.0"
 libc = "0.2.186"
+serde_json = "1.0.150"
 time = "0.3.49"
@@ -1,26 +1,24 @@
 use fuser::{
-    Errno, FileAttr, FileType, Filesystem, INodeNo, ReplyAttr, ReplyData, ReplyDirectory,
-    ReplyEntry, Request,
+    Errno, FileAttr, FileType, Filesystem, Generation, INodeNo, ReplyAttr, ReplyDirectory, Request,
 };
+use serde_json::{Map, Value, json};
+use std::collections::BTreeMap;
 use std::env;
 use std::path::Path;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::time::{Duration, SystemTime};

-struct JsonFilesystem;
-
-impl Filesystem for JsonFilesystem {
-    // For stat function like `stat /path/to/fuse`
-    fn getattr(
-        &self,
-        _req: &Request,
-        ino: fuser::INodeNo,
-        fh: Option<fuser::FileHandle>,
-        reply: ReplyAttr,
-    ) {
-        println!("getattr(ino={})", ino);
+struct JsonFilesystem {
+    tree: Map<String, Value>,
+    attrs: BTreeMap<INodeNo, FileAttr>,
+    inodes: BTreeMap<String, INodeNo>,
+}

+impl JsonFilesystem {
+    fn new(tree: &Map<String, Value>) -> JsonFilesystem {
+        let mut attrs = BTreeMap::new();
+        let mut inodes = BTreeMap::new();
        let ts = SystemTime::now();
        let attr = FileAttr {
            ino: INodeNo::ROOT,
@@ -40,13 +38,58 @@ impl Filesystem for JsonFilesystem {
            flags: 0,
        };

-        let ttl = Duration::new(1, 0);
+        attrs.insert(INodeNo(1), attr);
+        inodes.insert("/".to_string(), INodeNo(1));

-        if ino == INodeNo::ROOT {
-            reply.attr(&ttl, &attr);
-        } else {
-            reply.error(Errno::ENOSYS);
+        for (i, (key, value)) in tree.iter().enumerate() {
+            let attr = FileAttr {
+                ino: INodeNo(i as u64 + 2),
+                size: value.to_string().len() as u64,
+                blocks: 0,
+                atime: ts,
+                mtime: ts,
+                ctime: ts,
+                crtime: ts,
+                kind: FileType::RegularFile,
+                perm: 0o644,
+                nlink: 0,
+                uid: 0,
+                gid: 0,
+                rdev: 0,
+                blksize: 0,
+                flags: 0,
+            };
+
+            attrs.insert(attr.ino, attr);
+            inodes.insert(key.clone(), attr.ino);
        }
+
+        return JsonFilesystem {
+            tree: tree.clone(),
+            attrs: attrs,
+            inodes: inodes,
+        };
+    }
+}
+
+impl Filesystem for JsonFilesystem {
+    // For stat function like `stat /path/to/fuse`
+    fn getattr(
+        &self,
+        _req: &Request,
+        ino: fuser::INodeNo,
+        fh: Option<fuser::FileHandle>,
+        reply: ReplyAttr,
+    ) {
+        println!("getattr(ino={})", ino);
+
+        match self.attrs.get(&ino) {
+            Some(attr) => {
+                let ttl = Duration::new(1, 0);
+                reply.attr(&ttl, attr);
+            }
+            None => reply.error(Errno::ENOENT),
+        };
    }

    fn readdir(
@@ -61,17 +104,86 @@ impl Filesystem for JsonFilesystem {

        if ino == INodeNo::ROOT {
            if offset == 0 {
-                reply.add(INodeNo::ROOT, 0, FileType::Directory, &Path::new("."));
-                reply.add(INodeNo::ROOT, 1, FileType::Directory, &Path::new(".."));
+                let _ = reply.add(INodeNo::ROOT, 0, FileType::Directory, &Path::new("."));
+                let _ = reply.add(INodeNo::ROOT, 1, FileType::Directory, &Path::new(".."));
+                for (i, key) in self.tree.keys().enumerate() {
+                    let inode: u64 = 2 + i as u64;
+                    let offset: u64 = 2 + i as u64;
+                    let _ = reply.add(
+                        INodeNo(inode),
+                        offset,
+                        FileType::RegularFile,
+                        &Path::new(key),
+                    );
+                }
            }
            reply.ok();
        } else {
            reply.error(Errno::ENOSYS);
        }
    }
+
+    fn lookup(
+        &self,
+        _req: &Request,
+        parent: INodeNo,
+        name: &std::ffi::OsStr,
+        reply: fuser::ReplyEntry,
+    ) {
+        println!("lookup(parent={}, name={})", parent, name.display());
+
+        let inode = match self.inodes.get(name.to_str().unwrap()) {
+            Some(inode) => inode,
+            None => {
+                reply.error(Errno::ENOENT);
+                return;
+            }
+        };
+
+        match self.attrs.get(inode) {
+            Some(attr) => {
+                let ttl = Duration::new(1, 0);
+                reply.entry(&ttl, attr, Generation(0));
+            }
+            None => reply.error(Errno::ENOENT),
+        };
+    }
+
+    fn read(
+        &self,
+        _req: &Request,
+        ino: INodeNo,
+        fh: fuser::FileHandle,
+        offset: u64,
+        size: u32,
+        flags: fuser::OpenFlags,
+        lock_owner: Option<fuser::LockOwner>,
+        reply: fuser::ReplyData,
+    ) {
+        println!(
+            "read(ino={}, fh={}, offset={}, size={})",
+            ino, fh, offset, size
+        );
+
+        for (key, &inode) in self.inodes.iter() {
+            if inode == ino {
+                let value = self.tree.get(key).unwrap();
+                reply.data(value.to_string().as_bytes());
+                return;
+            }
+        }
+
+        reply.error(Errno::ENOENT);
+    }
 }

 fn main() {
+    let data = json!({
+        "foo": "bar",
+        "answer": 42,
+    });
+    let tree = data.as_object().unwrap();
+    let fs = JsonFilesystem::new(tree);
    let mountpoint = match env::args().nth(1) {
        Some(path) => path,
        None => {
@@ -90,7 +202,7 @@ fn main() {
    .expect("Error setting Ctrl+C handler");

    let cfg = fuser::Config::default();
-    let session = fuser::spawn_mount2(JsonFilesystem, &mountpoint, &cfg);
+    let session = fuser::spawn_mount2(fs, &mountpoint, &cfg);

    while running.load(Ordering::SeqCst) {
        std::thread::sleep(Duration::from_millis(100));